From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-ej1-f46.google.com (mail-ej1-f46.google.com [209.85.218.46]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6DB752686B7; Mon, 28 Apr 2025 13:48:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.218.46 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745848138; cv=none; b=J7L6WRvq+jiQIQd5kP00IXET9faYP6wd7Sut5lg4uDtXStXOOLSufp8bzaWdzG+fHw8gz2vqjcNA9B/qYpzVU7YpF0hQzKP4XD3TLkHHd+us8JSkqn8NCkXcs2EVhI7ZNuRl4ER/usqyZc5dPxjEdHGKt4A/fBVo0F4/STOWGlI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745848138; c=relaxed/simple; bh=HLTxekg6SxOcOsK/qGp+Wm+ZPRgavbtD8xBy8iyQaAI=; h=From:Date:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=OVhFR0BFT/4MwPSpzmPDac47E1rNa/2EaiLe2jrbFxPz870iCrFTerFFF7OEgR1MVjHmrJ+9KHYf/JnCI37cElXGpR0aJAXVpLFPd53tBe1iROS4UTdXoXtMd+YiV/lyBYNwhBPxM8Kgj+W09DT+Pybo+v02hD8xP1dzrFlMiu8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=JIrEO5hK; arc=none smtp.client-ip=209.85.218.46 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="JIrEO5hK" Received: by mail-ej1-f46.google.com with SMTP id a640c23a62f3a-ac2bdea5a38so687292466b.0; Mon, 28 Apr 2025 06:48:56 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1745848135; x=1746452935; darn=vger.kernel.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:date:from:from:to:cc:subject:date:message-id:reply-to; bh=Ot7zGl3RuBf7IRpQhd5mY289ZLMwSwI/eG9Lq7KXLoQ=; b=JIrEO5hKmCz1QHHKHCgvq4bPnUKhIrSHnOEsDX2U3pSF7dnS3C79+EIDjK83DRE84y 2ET1FHZUPr48vEroHSvLxL9lUuTE/33gPT16VR7pX9mjl0C5FhsWFi4Fy2Lfj9Nr6yGS u2TMVZ1u9en7c1xTgJbZPp5CO3K8D5uOzdrvFfmfuv0Dn9xS0O+011oiY/d/lX6eJXPZ 8hpPhouCu4/2400NEq6WqZjqD4vbk9bfgY0x7+5Ln3LRaoPLBBQX08hDUFTi1fGSOEHa 8iYwyaKbE/8o8uA8TkLHE1/YGoXzpIYXCRtRBIXaonnASlTwMQv45PcVkhFuQDSte38A Rozw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1745848135; x=1746452935; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:date:from:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=Ot7zGl3RuBf7IRpQhd5mY289ZLMwSwI/eG9Lq7KXLoQ=; b=Ojw+lrtXyY6UNezJT6qHyXnjeeoHJrSAkNYZ1xTv76e9aKl9JsVaBMNuRsez8Fp6tA T5DuktZR0EoVxzzHytzDe+tmXiUOhgRAFlKuV/o0uiYd+aY1bg41B2KTXZyycD5kREgW k0l+qsBMluve3A/z7XKEGAvqoMLWf6Up4wlyWMzW1Cn2IZmq25gpVNvEKkgCE8dvvfDH 0ADSRQ039vAqf4zmof9PGc0QCEN6cnXi/XAEnvh4IVtZxcpna6RefrjlfLb6t2YBRIqJ o7ww7wXzzMD83CmumeMyJZlvJT/aueut8fY1qQtj/A1D7PGmi9fnemiNJqecHBiV8Dcu XcQA== X-Forwarded-Encrypted: i=1; AJvYcCU3FjYy1uuwTBv60oBYb9g3SLiDxWAHD9f71qtIUtFlOYImYUhRSCjk1LiJsmEItl11Y09OnBV1XyFQQjv2@vger.kernel.org, AJvYcCXf1N92agAbv1WzS+8/Es84j2wtfvzm/6fEGliPekHWZOGZbWRIjJFM9rHQw1dVDqTCXtw=@vger.kernel.org, AJvYcCXgWG5xVocZYCK7L5AKbLDWwA3g+J+X8WCiwH9eWRfTV1zB8W+sTBK82zr5TLuFMYX1lNiaVRkfO0hSVEiLRXANlxq9@vger.kernel.org X-Gm-Message-State: AOJu0Yw8iC72xROQsgA24SMjLRnoGJxR8mZdFnfGVjtcIJfqtJF3fGwM PiZDDg7CdtFCxOOWDPDRozTLqj38VBn+Wp8+aBFu1sfQJtdMGa9+ X-Gm-Gg: ASbGncsqiClTTmhsWkyZbSBP8/1sBchrT+cro4L3CaWeMvc/ZD/0gwQ5btmZhl6lyki 4uLWHrrEHdqoGaDqg1LoJ3wn2AW9lHWvR+1oeYgnoh/A3lqYznVwNiN2XSd0bBHV7N9UvQOIn4l pIAs3DujP4kFUzmSTg6M2HphskJhwBq56bK33Lx19z/mFWVRIqPvh7oqulPMszEH8I/Gc/ZVofd CC6ayol1u5RfzIQTHf60oH2iz5EhRG0L2ihQ+vUPOEU6CJOITE8BL2reo27qzizXJn4MSeqSADP gjqqXGlAfxPs2dJCmZ4O3vcNnB8= X-Google-Smtp-Source: AGHT+IF2RIymO56/j4PaaIVUU5hWd33q98hmsID+T/QUTfZAQNdifbnv4XI4o7FGCL6y7RRKdXRf/A== X-Received: by 2002:a17:907:2cc2:b0:acb:5583:6fdd with SMTP id a640c23a62f3a-ace71048406mr802061866b.11.1745848134448; Mon, 28 Apr 2025 06:48:54 -0700 (PDT) Received: from krava ([173.38.220.34]) by smtp.gmail.com with ESMTPSA id a640c23a62f3a-acec3933a0dsm6497166b.21.2025.04.28.06.48.53 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 28 Apr 2025 06:48:54 -0700 (PDT) From: Jiri Olsa X-Google-Original-From: Jiri Olsa Date: Mon, 28 Apr 2025 15:48:51 +0200 To: Oleg Nesterov Cc: Peter Zijlstra , Andrii Nakryiko , bpf@vger.kernel.org, linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, x86@kernel.org, Song Liu , Yonghong Song , John Fastabend , Hao Luo , Steven Rostedt , Masami Hiramatsu , Alan Maguire , David Laight , Thomas =?iso-8859-1?Q?Wei=DFschuh?= , Ingo Molnar Subject: Re: [PATCH perf/core 08/22] uprobes/x86: Add mapping for optimized uprobe trampolines Message-ID: References: <20250421214423.393661-1-jolsa@kernel.org> <20250421214423.393661-9-jolsa@kernel.org> <20250427145606.GC9350@redhat.com> <20250427173456.GB27775@redhat.com> Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250427173456.GB27775@redhat.com> On Sun, Apr 27, 2025 at 07:34:56PM +0200, Oleg Nesterov wrote: > On 04/27, Oleg Nesterov wrote: > > > > On 04/21, Jiri Olsa wrote: > > > > > > +static unsigned long find_nearest_page(unsigned long vaddr) > > > +{ > > > + struct vm_area_struct *vma, *prev = NULL; > > > + unsigned long prev_vm_end = PAGE_SIZE; > > > + VMA_ITERATOR(vmi, current->mm, 0); > > > + > > > + vma = vma_next(&vmi); > > > + while (vma) { > > > + if (prev) > > > + prev_vm_end = prev->vm_end; > > > + if (vma->vm_start - prev_vm_end >= PAGE_SIZE) { > > > + if (is_reachable_by_call(prev_vm_end, vaddr)) > > > + return prev_vm_end; > > > + if (is_reachable_by_call(vma->vm_start - PAGE_SIZE, vaddr)) > > > + return vma->vm_start - PAGE_SIZE; > > > + } > > > + prev = vma; > > > + vma = vma_next(&vmi); > > > + } > > > + > > > + return 0; > > > +} > > > > This can be simplified afaics... We don't really need prev, and we can > > use for_each_vma(), > > > > static unsigned long find_nearest_page(unsigned long vaddr) > > { > > struct vm_area_struct *vma; > > unsigned long prev_vm_end = PAGE_SIZE; > > VMA_ITERATOR(vmi, current->mm, 0); > > > > for_each_vma(vmi, vma) { > > if (vma->vm_start - prev_vm_end >= PAGE_SIZE) { > > if (is_reachable_by_call(prev_vm_end, vaddr)) > > return prev_vm_end; > > if (is_reachable_by_call(vma->vm_start - PAGE_SIZE, vaddr)) > > return vma->vm_start - PAGE_SIZE; > > } > > prev_vm_end = vma->vm_end; > > } > > > > return 0; > > } > > Either way it doesn't look nice. If nothing else, we should respect > vm_start/end_gap(vma). > > Can't we do something like > > struct vm_unmapped_area_info info = {}; > > info.length = PAGE_SIZE; > info.low_limit = vaddr - INT_MIN + 5; > info.high_limit = vaddr + INT_MAX; > > info.flags = VM_UNMAPPED_AREA_TOPDOWN; // makes sense? so this would return highest available space right? current code goes from bottom now, not sure what's preffered > > return vm_unmapped_area(&info); > > instead ? yes, I did not realize we could use this, looks better, will try that thanks, jirka